Contact member and electrical device



1943! I w. W.WATROUS, JR 2,325,817

CONTACT MEMBER AND ELECTRICAL DEVICE Filed Dec. 10, 1941 INVETNTOP I M MIMI/r006, we.

BY m m ATTORNEY Patented Aug. 3, 1943 (JGNT'AC 'E AND EEESTREGAL DEVICE; Ward. W.. Watmus. Jr East oran e; J... assign:

arts. W stinghous le ric. a Manuta n na Company, East; Pittshurgh,fa,, a corporation Pennsyle ania fifi ember 11. claims. (Q1. ate-#2715); f

. This invention relates to. electronic tubes and other electrical devices,- such as rectifiers and amplifiers, and especially to. the metal contact cap: or base customarily cemented to. the en-. velope'. or bulb. of the device; and more particularlyto the formation of a good electrical connection between such a contact. capand a lead wire. 7

The conventional methodof forming'sucha connection istos'older the. lead wire to. the metal cap; but in actual practice this. method is sub-1 jject to certain disadvantages. and inconveniences:

which include, in. the first place, an inherent difliculty in makinga good soldered connection, due to-cxi'dation of the lead wires, such oxidation: being usually unavoidable owing'to. the exhaust process' to which the device is subiected.

In the second place, a gradual corrosion of the Another disadvantage of. a soldered union is that lithe cap be mounted upon the upper end of the device, the heat developedin the use of the latter rises and may destroy the union "byrnelti ing the solder.

' Under such conditions, it is a object.

of the invention to provide a method of male ing a good electrical connection between the lead.

wire and cap which will avoid the use of solder and corrosive material, thereby, eliminatingthe.

disadvantages above enunierated. and which at. the same time-preserves the advantages of a per-. manentmetallic union and good electrical connest-ion of the lead Wires to the cap.

. A-iuither object is to provide for Welding the lead wire to a suitable .metallic part of the cap structure, such part being either an originallyintegral portion of the ca'p,'o.r else a metal part.

oi suit'ahle contour and disposition integrated with the cap,'preferably by welding; 'l A still another object of the invention .to s construct the cap that the exterior terminal of thelead wire will be protected bya surrounding portion from casual mechanical contacts. tendinato. deform it. but. readily accessible for come. I

pleting the intended electricakconnection;

Otherfobjects and: advantages; oithe invention will. become apparent as description. proceeds.

In.- the drawing, p Fig. 1 is an elevational View. of an, electronictuhe in which the invention haiszhecn embodied.

. part. of the glass bulb orenvelope; being broken away to reveal inner structural details; I

Fig. 2 is an axial sectional View; on; an enlarged scale, of the contact. cap and adjacent part, of thetuhe shown in Fig. 1; Fig. 3 a plan View of the cap. ci: Figs- 1-v and 2;.

Fig; 4 is a5 view similar to. Fig. 2 of can-emhodyingthe invention;

Fig. 5. is, a. plan view of the cap. shown Fig.4; Fig. 6 is. aview to. Figs, 2 and 4%, showinganother 'modificationofi the. cap; and V Fig... Tisa plan view of the. can shown in Fig; 6.

a modified.

Referring now to the drawing in detail, thereis illustrated in Figs. 1, 2; and 3;. a Westinghouse It comprises. abulb' brand a conventional base. tsicnthelcathode t4 and grid t5: ..'ihe anode l6: a'supportingor relatively heavy or rigid lead it sealed through the. glass, as indicated at l&,

trantcup-shaped portion 2 2' defining a recess in which is disposed the. lead l-|,j in aj-central protected position as shown, with its exterior terminal standing somewhat below the plane of the, surrounding rimv of the can. readily accessible for suchelectrical connectionsas itmay be de..

sired to. make therewith, but guarded against. un-

desired physical contacts likely to deform it.

.In-pu'rsuance ofthesinvention, provision is made for perfecting -a-sturdy mechanical conned:v

tion, and a good electrical connection,'hy welding the leadv l'if directly to a suitable metalpart of thecapland' this may be carried out invarious ways, cf whichia desirableconstruction is shown in Figs. 2 and 3; another in Figs. 4' and 5; and still another in Figs; Sand 7"; these forms having'the' common purpose of making it possible to'* accomplish conveniently and positively a welding operationgpreferably in a suitable elec-' trical welding machine, that will provide a rigid .sccOmpanyKsu'ch' a metallic union.

Referring now more particularly to Figs. 2 and 3, it will be seen that the structure therein illustrated provides a metallic flange or tab 23 formed desirably by striking up the sheet metal inwardly embossed bottom portion 24 of the cap or cup-shaped contact device or base 20. Through the opening 2'! so made, the lead Wire ll passe to position to be conveniently, accurately and rapidly spot-welded, brazed, or otherwise suitably united metallically to the upstanding tab 2-3, it being understood that the opera- ,7

tion selected shall be performed without the use of metal of low melting point, such as solder, and soldering fluid or other corrosive material.

In the structure illustratedin'Figs. 4 and 5, W such tabs are shown at 25 and 26, having been struck up in position facing each other, being thus adapted to embrace and be united metallically to the lead wire ll which is first passed through'a centrally disposed aperture?! in the'bo-ttom of the cup-shaped re-entrant portion 24 ofthe base cap20 1 It is to be understood that in describing the tab 23 of the Figs. 1, 2 and 3 structure, and the tabs 25 and 26 of the Figs. 3 and 4 structure as of integral, struck-up formation, it is not intended to exclude the provision of separately formed uprights or 'tabs, which will themselves be united metallically to thebase cap as well as to the lead wire.

As an example of one such separately formed upright metal part, I have illustrated in Figs. 6 and 7 an eyelet or hollow boss 28, welded to the bottom of the base Cap 20 as at 29, the central bore 3110f this boss being in registry with a central aperture 3| in the. bottom of the base cap, through which aperture and bore the lead wire l'l is thrust, preparatory to being welded, substantially in the manner hereinbefore described in connection with the structures shown in Figs. 1to5 inclusive.

From the foregoing disclosure, it will be readily apparent to those skilled in the art, that by the provision of a permanent metallic union between the'lead wire l1, Il or ll and thebase or cap 20, 20 or 20 respectively, by welding the lead wire in each instance directly to an integral or welded metal part ofthe base cap, as to the tab 23 of the structure of Figs. 1, 2

. and 3, the tabs 25 and 26 of the structure of Figs. l and or the eyelet or hollow boss 28, itself integrated metallically withthe base cap, as in Figs. Sand '7, I have accomplished the various objects of the instant invention, as set forth .in' the opening paragraphs, and provided a permanently good j mechanical and electrical connection between thebase 'or cap and lead WireQfreefrom such latent sources of deterioration 'as corrosive fluid which is used in making soldered connections. ..Such soldering.,fluid results in. deterioration of the connection, unless all removed. l I

I vhave obviated in particular the disadvantage encounteredIheretofore when the cap is disposed at the'top of a tube, where solder or other readily f s b flm terial is apt to bemelted, destroying the connection. I have also effected a labor saving over the use of a soldered joint as spot welding may be performed in considerably less time, possibly about 50%, as compared with making a' soldered joint.

Although preferred embodiments "of my invention have been disclosed, it willbe understood that other modifications maybe made within the Spirit and scope of the appended claims I claim:

1. A contact member for the vitreous envelope of an electrical device comprising a metal cap for connection to said envelope around the exterior portion of a lead Wire therefrom, the central portion of said cap being offset inwardly from the peripheral portion, providing a re-entrant cup-shaped portion, the base of said reentrant portion having a part extending therefrom, terminating short of the plane of the outer surface of said peripheral portion, for welding to said lead beyond said aperture, thereby making it possible to avoid the use of readily fusible and corrosive materials which might result in deterioration of the connection.

A contact member for the vitreous envelope of an electrical device comprising a metal cap for connection to said envelope around the exterior portion of a lead wire therefrom, the central portion of said cap being offset inwardly from the peripheral portion, providing a re-entrant cup-shaped portion, the base of said reentrant portion having a tab struck therefrom, terminating short of the plane of the outer surface of said peripheral portion, for welding to said lead beyond said aperture, thereby making it possible to avoid the use of readily fusible and corrosive materials which might result in deterioration of the connection. r

'3. A contact member for an electrical device which has a vitreous envelope, comprising a generally cup-shaped metallic member adapted to fit said envelope and having an outstanding part adjacent an aperture to receive an electrode supporting lead wire therefrom to be integrated metallicly with said part by a relatively high melting point joint free from solder and corrosive fluxes.

4. A contact member for an electrical device having a vitreous envelope, comprising a metal cap adapted to be cemented to said envelope around the exterior portion of a lead wire, the central portion of said cap being ofiset inwardly from the peripheral portion, providing a reentrant cup-shaped portion, a pair of tabs struck from said central portion, and an aperture between said tabs in position to receive said lead, whereby said tabs may be welded to opposite sides of said lead.

5. A contact member for an electrical device having a vitreous envelope, comprising a generally cup-shaped metallic portion, with an inwardly offset bottom which i provided with an upright boss welded thereto, shorter than the offset distance, and having a central borein communication with an aperture in said bottom, said boss being provided to receive a lead wire anrl afford a convenient metal part to which it may be welded.

6. An electrical device comprising a vitreous envelope, electrodes enclosed therein, a lead wire extending from one of said electrodes through a seal in said envelope, 2. contact member cemented to said envelope around theexterior portion of said lead, said contact member comprising a'metal cap having a bas with an inwardly offset portion, an outstanding projection on said ofiset portion and an adjacent aperture receiving said lead wire, said lead wire being welded to said projection'beyond said aperture, thereby avoiding the use of readily fusible and corrosive materials which might result in deterioration of the connection. V Y W '7. An electrical device comprising a vitreous envelope, electrodes enclosed therein, an electrode supporting lead wire extending from one of said electrodes through a seal in said envelope, a contact member cementedto said envelope around the exterior portion of said lead, said contact member comprising a metal cap having a tab struck out from an inwardly offset base portion thereof and providing an aperture receiving said lead wire, said lead wire being welded to said tab beyond said aperture, thereby avoiding the use of readily fusible and corrosivematerials which might result in deterioration of the connection.

' 8. An electronic device comprising a vitreous envelope, electrodes enclosed therein and including a cathode, an anode comprising a plate, a relatively heavy lead wire extending therefrom, a grid, and a conventional lower base for said cathode and grid, said lead wire extending through a seal in the upper portion of said en'- velope, whereby when in operation a relatively large amount of heat is transmitted through said:

seal to the outer end of said lead wire, and a contact member for said lead Wire comprising a 1 metal cap cemented to said envelope around the exterior port-ion of said wire, the base-of said 7 cap being inwardly oiiset and having an aperture receiving said lead wire and providing a metal. part outstanding from said oiTset baseand adjacent said lead wire, said lead wire being welded to said part beyond said aperture, thereby avoiding the use of readily fusible and corrosivematerials which might result in deterioration of the connection.

9. A metal cap adapted to function as a contact member for connection with a projection on the vitreous envelope of an electrical device outwardly opening cup-shaped portion, the base 7 of said reentrant portion having an aperture one side of which is defined'by a flange struck therefrom to provide said'aperture, said flange allowing for welding said'lead thereto beyond said aperture'to avoid the use oflreadily fusibleand; corrosive materials which might result insubsequent deterioration of the connection.

10. An electrical device comprising a vitreous I cylindrical metal portionopen at one end to re- 7 ceive said projection and the other end tertion of the base of said cup-shaped portion being struck outto provide an aperture and adjacent flange, said lead wire being Welded to said flange between the insect said cup-shapedportion and.

the un-offset portion of said-wall, thereby avoiding the projection of any portion beyond th out o line of said contact member and the use of readily .fusible and corrosive materials'which might result in deterioration of the connection.

11. A contact member'for an electrical device having a vitreous envelope, comprising generally cup-shaped'metallic portion adapted. to a,

telescope with a portion of said envelope, the central portion of the bottom of said metallic portion being offset inwardly, apertured to receive a lead wire, and provided with an upright metallic .extension shorter than th offsetfldistance and to which said wire may be welded.

WARD W. wATRoUs, JR. 

